1990-8644 1990-8644 S1990-86442019000400187 Ecuador 00 12 2019 00 12 2019 15 69 187 191

2013 2 2 2 80-111 2011 16 2 2 2005 189-219 2015 2019 2013 2 3 3 377-98 2015 3 7-11 2013 2018 2007 1990 42-75